>> For Duchamp, "violating" the Mona Lisa was an integral part of the
>> artistic statement being made.
>
> Whatever Duchamp has done, I'm sure he did it more than 50 (70) years
> after Leonardo died.
He drew mustaches on a photograph of the painting, I think, and
exposed it.
He could show his photograph around because copyright had expired on
the painting, but moral rights do not expire, at least accoding to
Italian law (just stepped on that point today).
[FWIW, I'm positive we have no problem with moral rights and free software]